Wednesday 1 August 2012

No-till cropping can improve air quality, say scientists

California's Central Valley Business Times reports that experiments in the dry, wheat-growing palouse region of eastern Washington State might lead to cleaner air in the Central Valley of California.

Studies by U.S. Department of Agriculture (USDA) scientists show some no-till management systems can lower atmospheric levels of PM10 — soil particles and other material 10 microns or less in diameter that degrade air quality — that are eroded from crop fields by the wind. The findings could help reduce erosion and assist communities in complying with federal air quality regulations, the USDA says.

Agricultural Research Service (ARS) research leader Brenton Sharratt and ARS agronomist Frank Young conducted the research. “In the inland Pacific Northwest, when atmospheric levels of PM10 exceed federal limits, it’s usually because of erosion from farm lands,” says Mr. Sharratt. “Since the U.S. Environmental Protection Agency regulates air quality, farmers in this area are looking for ways to reduce erosion from their fields and assist communities in complying with regulations."

Farmers in the inland Pacific Northwest favour winter wheat-summer fallow production systems so that crops can germinate and grow during late summer and fall. But controlling weeds and conserving soil water during the summer can require up to eight tillage passes. This produces a dry, loose layer of fine soil particles that can be easily eroded by strong summer winds. “One major windstorm can generate enough airborne dust to exceed air quality standards for PM10,” says Mr. Sharratt. “But annual no-till cereal crops appear to be a viable strategy that farmers can use to control erosion and meet air quality regulations in the Pacific Northwest.” The next challenge is finding ways to make annual no-till crop systems as profitable as the current winter wheat/fallow system.

Read the rest of the article here.